1. Field of the Invention
The present invention relates to blind rivets having an internally located deformable sleeve section.
2. Prior Art
Blind rivets are well-known in the art and are used to fasten components when only one side of the workpiece is accessible. Such rivets generally comprise three pieces: (a) a stem or mandrel having a bulb-forming head at one end and serrations at the other end for engagement by a pulling tool; (b) a tubular body surrounding the mandrel and having a flanged head; and (c) a locking collar engaging the mandrel near the body head. In use, the head portion of the mandrel and the surrounding body together are inserted through a hole in the workpiece. A riveting tool including a pulling head is used to translate the mandrel axially away from the workpiece. During such translation, the bulb-forming elements of the mandrel expand the rivet body laterally to form a "blind bulb" on the hidden side of the workpiece. The pulling head then forces the locking collar into a groove in the mandrel to lock the headed, accessible end of the body to the stem. Finally, the stem portion of the mandrel extending from the workpiece is broken off to complete the installation.
One advance over such prior art blind rivet is disclosed in my U.S. Pat. No. 4,312,613, the disclosure of which is herein incorporated by reference. In that patent, a rivet assembly is disclosed comprising a mandrel, a rivet body, a buckling sleeve and a locking collar. The sleeve, rivet body and collar slideably disposed about the mandrel with the buckle sleeve disposed adjacent one end of the body and the mandrel extending through the body and beyond the other end of the body. The buckle sleeve has a generally cylindrical configuration such that when subjected to a pulling force, the sleeve buckles outwardly from the mandrel, slides about the rivet body and engages the workpiece. While such blind rivet assembly does contain a number of advantages over the prior art, yet further improvements are needed in order to keep pace with the development of new structural materials and the desires of the marketplace.